Problem: Simplify the following expression: $9\sqrt{325}$.
First, try to factor a perfect square out of the radical. $= 9\sqrt{325}$ $= 9\sqrt{25 \cdot 13}$ Separate the radical and simplify. $= 9\sqrt{25} \cdot \sqrt{13}$ $= 9 \cdot 5 \cdot \sqrt{13}$ $= 45\sqrt{13}$